Contribute to a Ruby on Rails project

A workspace set up to build and test a real open source Rails app: RubyUI, a component library with a Rails docs site. This guide forks it, installs Ruby with mise, runs its test suite, and starts its dev server — viewed privately with devmachine tunnel, with Claude Code on hand to help.

You need: a VPS (tested on Debian and Ubuntu), and a GitHub account.

Before you start: machine, skills, workspace

curl -fsSL https://mydevmachine.sh/install.sh | sh
devmachine setup
devmachine skills add
devmachine workspaces new components
devmachine sync

Already have a machine? Skip setup. Already have the workspace? Skip the last two. See getting started for what each command does.

By hand

1. Sign in to GitHub and add Claude Code

devmachine login gh
devmachine packages add claude-code --workspace components
devmachine sync

gh is already installed — it comes with every workspace’s dev package. login gh opens the sign-in in a real terminal; you finish it in your browser. See logins and secrets if this is your first login.

2. Fork and clone RubyUI

devmachine ssh components
gh repo fork ruby-ui/ruby_ui --clone
cd ruby_ui

gh repo fork --clone forks the repo to your GitHub account, using the login from step 1, and clones your fork.

3. Install Ruby with mise

mise use -g [email protected]
ruby -v

RubyUI’s CI runs on Ruby 3.3 and 3.4. mise compiles the version you ask for; the base package (part of essentials) already installed the headers and libraries — zlib1g-dev, libssl-dev, libyaml-dev, and the rest — that compiling Ruby needs, so this step does not fail on a missing header.

4. Install dependencies and run the gem’s tests

cd gem
bundle install
bundle exec rake

rake here runs RubyUI’s test suite and its standardrb linting in one step. This is the part of the repo you are most likely changing: the components themselves.

5. Run the docs app

cd ../docs
bundle install
pnpm install
bin/dev

The docs app is a Rails 8 site that also serves as RubyUI’s demo: it reads the gem straight from the path next to it, so a change to a component shows up in the docs app without reinstalling anything. bin/dev starts it on port 3000 and keeps running after you close the terminal — the SSH login was inside tmux.

6. View it privately

Back on your own computer:

devmachine tunnel components 3000

Open localhost:3000. Nothing is published — no DNS record, no open port — so this is safe to leave running while you work on a fork nobody else should see yet.

With your agent

Open a session on your own computer (devmachine skills add taught it the CLI) and say:

In my devmachine workspace components, fork and clone ruby-ui/ruby_ui with my
GitHub login, install Ruby 3.4 with mise, run the gem's test suite, and
start the docs dev server on port 3000.

The agent runs gh repo fork --clone, mise use -g [email protected], bundle install, bundle exec rake, and bin/dev over SSH, in that order. It needs devmachine login gh already done — a browser sign-in is not something it can do for you — and if it is not, the agent tells you to run it first. Once the dev server is up, it opens the tunnel with devmachine tunnel components 3000 and tells you to open localhost:3000.

Check it: bundle exec rake in gem/ passes with no failures, and localhost:3000 (through the tunnel) shows the RubyUI docs and component previews.

Source: ruby-ui/ruby_ui, ruby-ui/ruby_ui — CONTRIBUTING.md